On Thu, Jan 17, 2019 at 10:51 AM Tom Talpey <ttalpey@xxxxxxxxxxxxx> wrote: > > > -----Original Message----- > > From: linux-cifs-owner@xxxxxxxxxxxxxxx <linux-cifs-owner@xxxxxxxxxxxxxxx> On > > Behalf Of Xiaoli Feng > > Sent: Wednesday, January 16, 2019 6:36 PM > > To: Steve French <smfrench@xxxxxxxxx> > > Cc: CIFS <linux-cifs@xxxxxxxxxxxxxxx>; Xiong Zhou <xzhou@xxxxxxxxxx> > > Subject: How to make wsize=16M > > > > Hello Steve, > > From the mount.cifs man pages,the wsize can be 16M. I use samba server to > > test on upstream. > > But the wsize is always 8M if specify the wsize > 8M. How can I make > > wsize=16M? > > The maximum write size is a negotiated value, which is typically server-limited to > no more than 8MB. Here are some Windows-specific values, I'm sure Samba server > defaults are similar. > > https://msdn.microsoft.com/en-us/library/cc246805.aspx#Appendix_A_226 > > It's generally a bad idea to set a huge operation size. Such r/w operations tie up > the connection and cause many unpredictable and undesirable issues for other > traffic, in addition to the significant resources to marshal and unmarshal them. > > Tom. In my testing I found optimal for performance was 2MB or 4MB depending on server type, but we could use more data on whether there are servers or configurations for which defaulting to the larger value (8MB) improves performance (and whether such a server/network configuration could be detected automatically by the client). I didn't find any where 1MB or smaller was significantly better but that would be useful data as well. Default is currently 4MB and is easy to change on mount. > > My test: > > > > # uname -r > > 5.0.0-rc1+ > > # mount //localhost/test cifs -o > > user=root,password=redhat,wsize=16777216,vers=3.11 > > # mount |grep cifs > > //localhost/test on /root/cifs type cifs > > (rw,relatime,vers=3.1.1,cache=strict,username=root,domain=,uid=0,noforceuid, > > gid=0,noforcegid,addr=0000:0000:0000:0000:0000:0000:0000:0001,file_mode > > =0755,dir_mode=0755,soft,nounix,serverino,mapposix,rsize=1048576,wsize=83 > > 88608,echo_interval=60,actimeo=1,user=root) -- Thanks, Steve
